Ensure parameters.oustanding_kit does not drift far from the real value #156
Description
In the system parameters we keep track of the total amount of kit needed to close all currently open burrows via field outstanding_kit. However, this is only an approximation of the real amount. Not only we update the burrow.outstanding_kit field individually (per burrow) when touching burrows, but also burrows or checker might remain untouched for a while, which could introduce further rounding errors.
Errors of a few percents per year are NOT acceptable. Errors of 0.1% or so per year would be tolerable.
In order to test this meaningfully we should be able to create scenaria with many burrows, a lot of activity, and let a lot of time pass, which can be quite complicated to manufacture. Furthermore, one must keep track of all the burrows ever created to be able to inspect the storage and aggregate the total amount of outstanding kit for all burrows so that it can be compared to parameters.oustanding_kit.